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3

I'm guessing it means "Non-Magnetic" - as in "air-core" in lieu of "iron-core". There might be a particular RF frequency that the designer was trying to filter. However, I would guess that the designer was trying to filter all interference judging by the use of 4 sizes/types of filter caps on the power rail. But, really - I doubt an NM air-core inductor ...


1

I cannot say definitively, but I believe the most probably meaning of this label is "non-magnetic". This is because "non-mounted" would mean the temperature sensor power supply is not connected, which would cause the main IC to fail, since it needs proper temperature regulation to operate. I traced the signal line to the component on the physical board, ...


5

Maybe "NO MOUNT"? Is the supply connection optional? “Non-Magnetic” doesn’t make sense, at least at first look. All inductors are “magnetic” in that they use flux to work. That’s said, I could see how they meant that as a stand-in for air core, so I’ll pile on to that answer too.


1

First, one misconception to clear up. You said: as the Vs (which should be a square wave) massively droops and therefore the Vho is too small to turn on the high side MOSFET for the normal time expected. However, you have a boot-strapped driver. It maintains a Vgs of about 15V (from VCC) at the gate. If you plotted both v(ho) and v(s) on the same graph, ...


6

In these situations for prototyping I do something like this: You cut the traces on the PCB if you need to install the choke. That way you don't impedance problems from soldering wires. The problem with this setup is once you cut the PCB traces, you can't go back. Another way to do this would be to put 0 ohm resistors in series with the choke. Or you could ...


2

It would be a dual pad layout joined for either SMD CM choke or any SMD 0R parts or fixed R parts depending on design. The design would be controlled impedance for USB2 (100MHz) or USB 3.


1

In theory forever, there is no off state discharge path. In this application, for safety, you should provide a high value bleed resistor across the capacitor then your discharge time is determined by that value the capacitor value your start voltage and at what voltage you consider the capacitor discharged.


1

Don't get confused! RPM is the rotation speed measure. Rotation speed is proportional to the Electormotion Force, which is voltage (Volts), not power (mW). Power is voltage times current (A) . What current will your generator provide? Well, in wide range, it will be the exact current you take, nothing more, nothing less. That's it. If you come closer to ...


0

This is an interesting question and probably has a good solution available once you supply all the information that is relevant that you know but that, so far, we don't. SO - this is a brief interim answer based on what you have told us. If you add more detail and explanation the answer can be improved. Otherwise, this is about as good an answer as you can ...


2

An idea... If the diode anodes weren’t tied to GND, what happens? You get a large, negative voltage through each diode when each transistor turns off and the coil flux collapses. Add a capacitor to capture the charge and you just made an inverting boost converter. Rearrange things a bit: put the npn’s on the low side and connect the coils to the supply, ...


2

For anyone interested, the issue turned out to be layout related. It seems the feedback signal was such a high impedance, with the most sensitive part running near the transformer, noise was coupling into the system and being amplified. There is an effective ~100x amplification of noise after the high voltage divider created by R9,10 & TM1 on the output....


1

This is a great question Colin, one which I puzzled over long and hard myself before coming to an intuitive understanding. Magnetizing inductance and magnetizing current are two aspects of the same departure of a real transformer from the ideal transformer model; in particular, as you mention, the fact that a real transformer core has finite permeability. ...


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Reality is this - if you apply a voltage source to the primary of a transformer then the phase difference between primary voltage (dot end) and secondary voltage (dot end) is zero. In other words the dots tell you about the phase relationship between primary wires and secondary wires. Because of this, if you have a load resistor connected to the secondary, ...


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